How can I store data from a plot in an ASCII text file when I have more than one line plotted in MATLAB?

My axes contains more than one line object and I want to write the data from that axes containing the line objects into an ASCII text file. For example:

clc

clear

x = 1:10;

y1 = x;

y2 = sin(x);

y3 = cos(x);

plot(x,y1,...

x,y2,...

x,y3);

% clearing all existing varibles

clc

clear

% get handle to current axis 

line_handle=findall(gca,'Type','line');

x=get(line_handle,'XData');

y=get(line_handle,'YData');

% saving file in ASCII text

save mydata.txt x y -ascii

When I execute the above code I get the following error:

%%%BEGIN WARNING MESSAGE%%%

Warning: Attempt to write an unsupported data type to an ASCII file.

Variable 'x' not written to file.

Warning: Attempt to write an unsupported data type to an ASCII file.

Variable 'y' not written to file.

%%%END WARNING MESSAGE %%%

Answer 1

[MathWorks Support Team]

When more than one handle is passed to the GET function, MATLAB stores the data in the form of cell arrays. For example, if you use:

y = get(h, ‘YData’);

and h is a scalar then y is returned as a vector. When h is a vector then y is returned as a cell array. These cell arrays cannot be stored as ASCII files using the SAVE function in MATLAB. To convert the cell arrays into matrices that can be stored in an ASCII file, add the following lines of code to the above example:

% converting date type from CELL to MAT

xx = cell2mat(x);

yy = cell2mat(y);

save mydata.txt xx yy -ascii

The complete code with the appended lines is as follows:

clc

clear

x = 1:10;

y1 = x;

y2 = sin(x);

y3 = cos(x);

plot(x,y1,...

x,y2,...

x,y3);

% clearing all existing varibles

clc

clear

% get handle to current axis 

line_handle=findall(gca,'Type','line');

x=get(line_handle,'XData');

y=get(line_handle,'YData');

% converting date type from CELL to MAT

xx = cell2mat(x);

yy = cell2mat(y);

% saving file in ASCII text

save mydata.txt xx yy -ascii